mirror of https://gitee.com/openkylin/linux.git
126 lines
3.3 KiB
C
126 lines
3.3 KiB
C
/*
|
|
* Idle functions for s390.
|
|
*
|
|
* Copyright IBM Corp. 2014
|
|
*
|
|
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/kernel_stat.h>
|
|
#include <linux/kprobes.h>
|
|
#include <linux/notifier.h>
|
|
#include <linux/init.h>
|
|
#include <linux/cpu.h>
|
|
#include <asm/cputime.h>
|
|
#include <asm/nmi.h>
|
|
#include <asm/smp.h>
|
|
#include "entry.h"
|
|
|
|
static DEFINE_PER_CPU(struct s390_idle_data, s390_idle);
|
|
|
|
void enabled_wait(void)
|
|
{
|
|
struct s390_idle_data *idle = this_cpu_ptr(&s390_idle);
|
|
unsigned long long idle_time;
|
|
unsigned long psw_mask;
|
|
|
|
trace_hardirqs_on();
|
|
|
|
/* Wait for external, I/O or machine check interrupt. */
|
|
psw_mask = PSW_KERNEL_BITS | PSW_MASK_WAIT | PSW_MASK_DAT |
|
|
PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
|
|
clear_cpu_flag(CIF_NOHZ_DELAY);
|
|
|
|
/* Call the assembler magic in entry.S */
|
|
psw_idle(idle, psw_mask);
|
|
|
|
/* Account time spent with enabled wait psw loaded as idle time. */
|
|
idle->sequence++;
|
|
smp_wmb();
|
|
idle_time = idle->clock_idle_exit - idle->clock_idle_enter;
|
|
idle->clock_idle_enter = idle->clock_idle_exit = 0ULL;
|
|
idle->idle_time += idle_time;
|
|
idle->idle_count++;
|
|
account_idle_time(idle_time);
|
|
smp_wmb();
|
|
idle->sequence++;
|
|
}
|
|
NOKPROBE_SYMBOL(enabled_wait);
|
|
|
|
static ssize_t show_idle_count(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
|
|
unsigned long long idle_count;
|
|
unsigned int sequence;
|
|
|
|
do {
|
|
sequence = ACCESS_ONCE(idle->sequence);
|
|
idle_count = ACCESS_ONCE(idle->idle_count);
|
|
if (ACCESS_ONCE(idle->clock_idle_enter))
|
|
idle_count++;
|
|
} while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence));
|
|
return sprintf(buf, "%llu\n", idle_count);
|
|
}
|
|
DEVICE_ATTR(idle_count, 0444, show_idle_count, NULL);
|
|
|
|
static ssize_t show_idle_time(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
|
|
unsigned long long now, idle_time, idle_enter, idle_exit;
|
|
unsigned int sequence;
|
|
|
|
do {
|
|
now = get_tod_clock();
|
|
sequence = ACCESS_ONCE(idle->sequence);
|
|
idle_time = ACCESS_ONCE(idle->idle_time);
|
|
idle_enter = ACCESS_ONCE(idle->clock_idle_enter);
|
|
idle_exit = ACCESS_ONCE(idle->clock_idle_exit);
|
|
} while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence));
|
|
idle_time += idle_enter ? ((idle_exit ? : now) - idle_enter) : 0;
|
|
return sprintf(buf, "%llu\n", idle_time >> 12);
|
|
}
|
|
DEVICE_ATTR(idle_time_us, 0444, show_idle_time, NULL);
|
|
|
|
cputime64_t arch_cpu_idle_time(int cpu)
|
|
{
|
|
struct s390_idle_data *idle = &per_cpu(s390_idle, cpu);
|
|
unsigned long long now, idle_enter, idle_exit;
|
|
unsigned int sequence;
|
|
|
|
do {
|
|
now = get_tod_clock();
|
|
sequence = ACCESS_ONCE(idle->sequence);
|
|
idle_enter = ACCESS_ONCE(idle->clock_idle_enter);
|
|
idle_exit = ACCESS_ONCE(idle->clock_idle_exit);
|
|
} while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence));
|
|
return idle_enter ? ((idle_exit ?: now) - idle_enter) : 0;
|
|
}
|
|
|
|
void arch_cpu_idle_enter(void)
|
|
{
|
|
local_mcck_disable();
|
|
}
|
|
|
|
void arch_cpu_idle(void)
|
|
{
|
|
if (!test_cpu_flag(CIF_MCCK_PENDING))
|
|
/* Halt the cpu and keep track of cpu time accounting. */
|
|
enabled_wait();
|
|
local_irq_enable();
|
|
}
|
|
|
|
void arch_cpu_idle_exit(void)
|
|
{
|
|
local_mcck_enable();
|
|
if (test_cpu_flag(CIF_MCCK_PENDING))
|
|
s390_handle_mcck();
|
|
}
|
|
|
|
void arch_cpu_idle_dead(void)
|
|
{
|
|
cpu_die();
|
|
}
|